nearer together, and coming to be immediately contiguous, do mutually adhere, and are concreted so as to produce that Chalk or tophaceous Matter which is in some arthritick Cases to be observed. And as the _Coagulum_, which may be made by an Acid austere, seems apt to make a Concretion of that nature, so the Colour of the tophaceous Matter doth answer to that of this Coagulation, so as to seem generated in this Manner. SECT. 9. The same Author explains the Reason why the Hands and Feet are most subject to this Disorder. In the Hands, as was shewn before, there not only are considerable Glands in all their Joints, but the Tendons which are there inserted, especially those of the _Musculi perforantes_, have their mucilaginous Glands, so that Nature hath a convenience in these Parts to depurate the Mass of Blood, and they must receive the morbifick Matter, when the Blood in its Circulation obtrudes it upon them, and the Glands are disposed to separate it. The same Thing may be observed of the Shoulder and of the Knees. But of all the Parts none are so frequently afflicted with this Disease as the Feet, and it is plain why they are so. For besides, that they have many mucilaginous Glands in their Joints, and others about the Tendons which are inserted into their Bones, as the great Chord or Tendon of the Muscles which extend the Foot, and those of the _Perforantes_; I say besides this, they are the inferior and pendulous Parts, so that as their Glands make them capable of entertaining, so their Situation does conspire with the Effort of Nature, to bring down the morbifick Matter into them. Thus far Dr. _Havers_, whom I have chosen to quote, because he hath exceeded all Authors in treating of the Nature of this Distemper. It is not necessary to add any more upon this Head. What I have omitted for Brevity’s Sake, the Reader may find in my _Encyclopædia Medica_, where I have treated of the Cause of this Distemper, and evidently shewed how from the Glands and Lymphatick Ducts about the Membranes and nervous Parts of the Joints, a large Quantity of sharp _Serum_ and other lixivial and acid Particles or other morbid Matter thickning and corrupting the Lymph, is secreted and deposited upon the Joints, where they corrode and vellicate the nervous Fibres. Upon the Addition of Particles more than ordinary acid, the Pains become more durable and fixed; insomuch as Salts of different Natures become jumbled together, and from the Agitation and Conflict of the Particles, the Membranes are vellicated and distended in a very painful Manner; neither doth the Pain abate till the Particles get forth of the Glands, or their Conflict being over, leave the Spirits at rest. CHAP. V.